The invention relates to a method of heating the interior of a vehicle, particularly of a hybrid or electric vehicle, the vehicle having a central heating system and several decentralized heating surfaces constructed as infrared radiators, and the temperature of the vehicle interior being controllable by the central heating system and/or the decentralized heating surfaces corresponding to a heating demand of at least one vehicle occupant.
Currently, the temperature of most vehicles is controlled by use of a conventional heating and cooling system corresponding to the driver's demands. In addition to having this conventional heating system, many vehicles are also equipped with a seat heating system, which can be activated by the driver or by the person situated in the seat. This seat heating system only sets the temperature of the seat corresponding to the adjusted activation stage and is controlled completely independently of the conventional heating/cooling system is set.
From the prior art, in addition to the conventional heating system, electric heating systems are also known for setting the temperature of the vehicle interior. Thus, German Patent Document DE 198 08 571 B4 discloses a heating device in addition to the conventional heating and air-conditioning system, which additional heating device consists of at least one infrared radiator which is installed in the vehicle interior in the manner of a decentralized heating system. The heat output of the infrared radiator can be automatically controlled by a corresponding automatic control device, which controls a heat output of the infrared radiator and the heat output of the conventional heating system.
Furthermore, from German Patent Document DE 10 2011 077 993 A1, a vehicle having a heating and cooling system is known, in which case at least a part of the heating and cooling system is arranged in a decentralized manner in the proximity of the individual seat areas of the vehicle. In this case, the control of the decentralized heating and cooling system takes place as a function of the seat occupation.
It is an object of the invention to provide an improved method of heating the interior of a vehicle by way of a central heating system and a decentralized heating system.
This and other objects are achieved by a method of heating the interior of a vehicle, particularly of a hybrid or electric vehicle, the vehicle having a central heating system and several decentralized heating surfaces constructed as infrared radiators. The temperature of the vehicle interior is controllable by the central heating system and/or the decentralized heating surfaces corresponding to a heating demand of at least one vehicle occupant. For controlling the temperature of the vehicle interior corresponding to the heating demand by way of the central heating system and/or the decentralized heating surfaces, a power distribution takes place between the central heating system and the decentralized heating surfaces as a function of specified distribution demands. The method according to the invention as well as its advantageous further developments can be implemented by way of an algorithm or a corresponding arrangement of assemblies in a control device provided for that purpose.
The invention is based on the fact that the vehicle, in which the method according to the invention is to be used for heating the interior of a vehicle, has several decentralized heating surfaces in addition to a conventional central heating system, the decentralized heating surfaces being designed as infrared heating surfaces.
The infrared heating surfaces may be constructed and further developed such that the actual infrared radiator, which consists, for example, of a foil, which is further developed as a radiation generator and through which current flows, on the backside facing away from the vehicle interior, borders on an insulation layer and, on the front side facing the vehicle interior, borders on a heat-transmitting decorative surface, so that the occupant is protected from direct contact with the infrared radiator. The heating surfaces may be arranged at different points in the vehicle interior, for example, in the door panel, in the floor covering, in the area of the center console, in the knee area, in the area of the A-, B-, or C-pillar, the elbow space, the vehicle ceiling, on the front side of the seats or at the rearward covering of the seats, the tunnel or the lateral surfaces of the armrests.
By use of such infrared heating surfaces, an immediate warming of the occupants without any air movement and without any noise can take place by the direct energy transmission of the infrared radiation.
It is the basic idea of the invention to achieve a controlling of the temperature of the interior that is optimal with respect to the occupants' demands, by means of a suitable power distribution between the conventional central heating system and the decentralized heating surfaces. According to the invention, this can be achieved in that, for controlling the temperature of the vehicle interior corresponding to the heating demand, a power distribution takes place between the central heating system and the decentralized heating surfaces as a function of specified distribution demands.
The distribution demand may be specified by different alternatives. According to a first alternative, the power distribution can take place as a function of a manually and/or automatically adjustable distribution prompt, i.e, either the driver can manually set a defined distribution demand, or, on the basis of an analysis of defined parameters, an automatic distribution prompt can be set.
For the manual adjusting of the power distribution between the heating surfaces and the conventional heating system, a slider control may, for example, be provided by whose actuation the driver can define a certain percentage for the heating power, which is to take place or to be generated by a corresponding actuating of the decentralized heating surfaces. In the extreme positions, the entire heating power may be generated only by the conventional central heating system or only by the decentralized heating surfaces.
In contrast to the power distribution as a function of a manually adjustable distribution demand, as an alternative, the distribution demand can also take place automatically by way of predefined marginal conditions and/or currently existing demands and parameters. In particular, the automatic distribution demand or the power distribution can take place such that the temperature in the vehicle interior can be controlled as efficiently as possible corresponding to the heating demand. For example, in this case, the temperature in the vehicle interior can be controlled as efficiently as possible with respect to the energy consumption, with respect to comfort or with respect to a combination of energy consumption and comfort.
Since, by use of the infrared heating surfaces, the interior can be heated very rapidly, particularly a person situated close to the actuated heating element can be warmed, the method may be further developed such that, for reasons of comfort, an actuating of the infrared heating surfaces should basically be preferred. However, under certain circumstances, this could result in an increased energy requirement, which, in turn, should be avoided for reasons of energy efficiency.
In order to be able to achieve a temperature control that is as efficient as possible by use of a corresponding power distribution to the conventional central heating system and the decentralized heating surfaces, the method may also include a computation of the desired heating power of the infrared heating surfaces corresponding to the temperature control demands. This desired heating power of the decentralized heating surfaces can, in this case, be determined as a function of the thermal condition of the interior and/or of a specified desired temperature or of a set desired value (customer setting), and/or possibly also as a function of the current outside temperature. In this case, the thermal condition of the interior in comparison to the set desired value can be determined as a function of the following parameters:
(a) Current temperature in the vehicle interior, and/or
(b) heat output desired by the occupant, which, in turn can be determined by a thermo-physiologically-physically oriented computation.
A corresponding computation method for determining the thermal condition of the interior is disclosed, for example, in German Patent Document DE 10 2009 007 414 A1.
The above-mentioned determined desired heat output quantity can be provided by an optimal distribution to the decentralized heating surfaces. Only the residual requirement of heating power is supplied by way of the conventional heating system; i.e. the heating power of the conventional heating system is reduced to an extent in which the heating power can be provided by the operation of the heating surfaces. As a result, optimal comfort is achieved in the case of a minimal electric energy requirement.
Advantageously, the temperature control in the interior or the power distribution can also be influenced as a function of the number of occupants of the vehicle, particularly such that, when occupied passenger seats are recognized, only the heating surfaces in the area of those occupied occupant seats are activate. The heating surfaces that are arranged in the area of unoccupied occupant seats, are not actuated.
Advantageously, the power distribution can also be influenced as a function of the measured power consumption and/or the power consumption to be expected of the central heating system and/or of the decentralized heating surfaces, particularly as a function of the measured power consumption and/or the power consumption of the decentralized heating surfaces that is to be expected, relative to the possible power output of that onboard power supply system that supplies the energy for actuating the decentralized heating surfaces. When it is, for example, determined that the electric power consumption (for example, measured) or the electric power consumption of the decentralized heating surfaces to be expected exceeds a maximally possible power output of an onboard power supply system (such as the low-voltage system (12 V or 48 V), to which the heating surfaces are connected, the power distribution has to be adapted such that a displacement of the heating power takes place in the direction of the conventional heating system, particularly a complete switching-over to the conventional heating operation. The assumption of an exceeding of the electric power demand of the heating surfaces beyond the maximally possible electric power output of the onboard power supply system supplying the power can take place in the simplest manner, for example, by determining and analyzing the occupied seats in the vehicle. If it is determined that (almost) all seats are occupied, and correspondingly (almost) all decentralized heating surfaces should be actuated (which results in a high electric energy consumption), a switching-over can already take place ahead of time to the purely conventional heating operation by way of the central heating system. As an alternative, the switching-over can also already take place when a lower number of persons (for example, 2 persons in the vehicle) is exceeded.
As an alternative to the influencing of the power distribution as a function of the comparison of the measured or assumed electric power consumption of the heating surfaces to be activated and the electric power output of the relevant onboard power supply system, the power distribution can also be influenced or specified as a function of the measured power consumption or the electric power consumption to be expected of the decentralized heating surfaces in comparison to the measured power consumption or the electric power consumption to be expected of the conventional central heating system. When, for example, the electric power consumption of the infrared heating surfaces (in the case of a corresponding seat occupation) or the sum of the electric power consumption of the infrared heating surfaces and of the conventional heating system (in the correspondingly reduced operation) exceeds the actual power consumption or the power consumption to be expected of the conventional heating system in the case of a conventional heating of the interior (thus, without any actuating of the heating surfaces), a switching-over in the direction of a conventional heating operation by way of the central heating system can also take place; i.e. the interior is heated more conventionally and less, or not at all, by way of heating surfaces.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.